Aircraft Jack Repair & Maintenance: What Every Operator Should Know

Key Takeaways

1. Aircraft jacks are critical GSE used to support aircraft during maintenance, passenger deplaning, and weighing procedures – and like the aircraft they support, they require regular, professional servicing to operate safely.
2. The two primary jack types – axle jacks and tripod jacks – serve distinct purposes: axle jacks target landing gear work, while tripod jacks lift the entire aircraft at designated jacking points for broader fuselage and nose maintenance.
3. Tronair recommends a 90-day inspection and an annual load test for all aircraft jacks. Skipping these intervals isn't just a maintenance oversight – it's a safety risk.
4. Visual inspection alone isn't enough to determine whether a jack is safe to use. Only a trained, authorized service technician can properly evaluate the jack's condition and certify it for use.
5. As an authorized Tronair distributor and service center, PJi performs both 90-day inspections and 12-month load tests, keeping your jacks compliant, certified, and ready to work.

Aircraft jacks don't get nearly as much attention as the aircraft they support – but they should. A jack that looks fine on the outside can be hiding hydraulic issues, structural fatigue, or seal degradation that only becomes apparent when it fails. And when a jack fails mid-lift, the consequences can be catastrophic – for the aircraft, the ground crew, and the operator.

That's why routine servicing by authorized GSE technicians isn't optional – it's a fundamental part of keeping aircraft and personnel safe. In this article, we'll walk through the use cases that aircraft jacks support, the two main jack types you'll see on the flight line and maintenance floor, and the 90-day and 12-month service routines that Tronair recommends to keep every jack in your fleet safe and certified.

Aircraft Jacks 101: Use Cases and the Two Main Types

Aircraft jacks are one of the most essential pieces of ground support equipment on any flight line or maintenance floor. They provide stable, reliable support for aircraft in a stationary state, enabling maintenance teams to perform inspections, repairs, and service procedures safely and efficiently. Beyond standard maintenance lifts, jacks also stabilize the tail of an aircraft during passenger deplaning to prevent tail-tipping and assist with lowering the aircraft onto scales and load cells for weight-and-balance measurements. In short, aircraft jacks support your aviation investment – literally and figuratively.

Two main jack types handle the bulk of this work: axle jacks and tripod jacks. Axle jacks lift individual landing gear assemblies for single-gear tasks, while tripod jacks engage the aircraft's designated jacking points to raise the entire airframe for broader inspection, maintenance, and repair work. Each type has its own use cases and service routines, which we'll explore in detail below.

Both types are portable, self-contained hydraulic units – and both can hide serious issues behind a perfectly normal-looking exterior. A jack in poor condition often looks just like one in perfect condition, which is why routine aircraft jack repair, inspection, and maintenance by a qualified technician is the only reliable way to confirm a unit is safe to use.

Routine Service Checklists for Your Tronair Jacks

Tronair aircraft jacks are trusted worldwide for their reliability, precision, and long service life – but like any high-performance GSE, they only stay that way with regular professional attention. Tronair recommends a 90-day routine inspection and an annual load test for every aircraft jack in service, regardless of type or capacity. These intervals aren't arbitrary – they're designed to catch hydraulic leaks, structural fatigue, and seal wear before they turn into safety events.

As an authorized Tronair distributor and GSE service center, Pilot John International® (PJi®) is equipped to perform both the 90-day inspections and annual load tests on your axle jacks, single-stage tripod jacks, and multi-stage tripod jacks. Our certified GSE technicians follow Tronair's published service procedures and document every inspection, keeping your records audit-ready. Learn more about PJi’s full range of GSE services – or use the checklists below to understand exactly what's covered at each interval.

Axle Jacks

Axle jacks are positioned directly beneath the aircraft's landing gear and are typically used for single-gear lifts, such as tire changes, brake service, and wheel-and-bearing work. Because they carry the full weight of one gear assembly on every lift, their hydraulic system and structural components experience concentrated stress that requires regular professional inspection. Here's what Tronair's 90-day and 12-month service routines cover for axle jacks:

90-Day Maintenance Checklist

• Check the hydraulic system for leaks, including:
  • Hand pump – cylinder, fittings, and seals
  • Reservoir – welds and fittings
• Inspect the jack structure for corrosion, bending, cracking, and excessive wear, including:
  • Base plate
  • Mechanical extension
  • Hydraulic cylinder assembly
  • Retaining ring (secures the cylinder to the base plate)
  • Jack pads, nose, and main gear adapters
  • Spacer blocks
• Check fluid level with rams fully retracted (refer to the manual for the correct level height).
• Extend rams and visually inspect for corrosion, foreign matter, excessive wear, and leaks around ram seals; remove any foreign matter.
• Check paint condition and touch up exposed areas.
• Actuate the hand pump and raise the ram to full extension at least once.
• Do not pressurize the hydraulic system once fully extended.
• Do not allow the jack to misstage when raising the rams to full extension.
• Open the release valve and verify that the rams fully retract.

Annual (12-Month) Maintenance Checklist

• Check hydraulic fluid for contamination (dirt/water) – drain and flush if required.
• Perform the full 90-day maintenance checklist.
• Conduct a capacity test at 110% of the jack’s rated capacity.

Single-Stage Tripod Jacks

Single-stage tripod jacks use a single hydraulic ram to lift the aircraft – the most common configuration for lighter business and general aviation airframes. The single-stage design keeps the lift mechanism relatively simple, but the hydraulic system, structural welds, ball-lock pins, and lift components still need consistent inspection to stay within Tronair's safety specifications. Here's what's covered at the 90-day and 12-month intervals:

90-Day Maintenance Checklist

• Check the hydraulic system for leaks, including:
  • Hydraulic lines – hoses and fittings
  • Hand pump – cylinder, fittings, and seals
  • Reservoir – welds and fittings
  • Air-operated pump (optional equipment) – fittings, airside and oil side seals
• Inspect the jack structure for corrosion, bending, cracking, and excessive wear, including:
  • Ball-lock pins
  • Mechanical extension
  • Welded joints, tripod legs, cylinder, and foot pads
  • Ram lock nuts
  • Gouge marks and cracks in the threads
  • Jack pads
• Check the fluid level with the rams fully retracted (the proper level height is listed in the manual or on the reservoir tag).
• Extend rams and visually inspect for corrosion, foreign matter, excessive wear, and leaks around ram seals; remove any foreign matter.
• Check the air-operated pump, if equipped (refer to the air-operated pump service manual).
• Check paint condition and touch up exposed areas.
• Actuate the hand pump and raise the ram to full extension at least once.
• Do not overpressurize the system once fully extended.
• Apply DoAll, RPM, LPS, or an equivalent Buna-N-compatible water repellent to the rams.
• Open the release valve and verify that the rams fully retract.
• Lubricate casters (if applicable).
• Torque the ram retaining cap.

Annual (12-Month) Maintenance Checklist

• Check hydraulic fluid for contamination (dirt/water) – drain and flush if required.
• Perform the full 90-day maintenance checklist.
• Conduct a capacity test at 105% to 110% of the jack’s rated capacity.

Multi-Stage Tripod Jacks

Multi-stage tripod jacks use multiple telescoping rams to reach greater lift heights than single-stage units – making them the standard choice for larger commercial and business aircraft that require extra clearance for landing gear retraction tests and full-fuselage maintenance. The added complexity of the telescoping ram assembly creates more wear points to inspect and more components that can affect safe operation, which is why disciplined adherence to Tronair's service intervals is even more important. Here's what the 90-day and 12-month routines cover:

90-Day Maintenance Checklist

• Check the hydraulic system for leaks, including:
  • Hydraulic lines – hoses and fittings
  • Hand pump – cylinder, fittings, and seals
  • Reservoir – welds and fittings
  • Air-operated pump (optional equipment) – fittings, airside and oil-side seals
• Inspect the jack structure for corrosion, bending, cracking, and excessive wear, including:
  • Ball-lock pins
  • Mechanical extension
  • Welded joints, tripod legs, cylinder, and foot pads
  • Ram retaining rings
  • Ram lock nuts
  • Gouge marks and cracks in the threads
  • Jack pads
• Check the fluid level with the rams fully retracted (the proper level height is listed in the manual or on the reservoir tag).
• Extend rams and visually inspect for corrosion, foreign matter, excessive wear, and leaks around ram seals; remove any foreign matter.
• Check the air-operated pump, if equipped (refer to the air-operated pump service manual).
• Check paint condition and touch up exposed areas.
• Actuate the hand pump and raise the ram to full extension at least once, with a minimum weight of 50 lbs applied.
• Do not pressurize the hydraulic system once fully extended.
• Do not allow the jack to misstage when raising the rams to full extension.
• Apply DoAll, RPM, LPS, or an equivalent Buna-N-compatible water repellent to the rams.
• Open the release valve and verify that the rams fully retract.
• Lubricate casters (if applicable).

Annual (12-Month) Maintenance Checklist

• Check hydraulic fluid for contamination (dirt/water) – drain and flush if required.
• Perform the full 90-day maintenance checklist.
• Conduct a capacity test at 105% to 110% of the jack’s rated capacity.

The Bottom Line

Aircraft jacks are too critical – and too consequential when they fail – to leave to chance. Understanding the use cases of each jack type, sticking to Tronair's recommended 90-day inspection and annual load test schedule, and partnering with an authorized service center are the most reliable ways to keep your jacks safe, certified, and ready to lift when your team needs them.

At PJi, we maintain a comprehensive selection of new, used, and refurbished aircraft jacks – including axle jacks and tripod jacks – from Tronair and its subsidiaries, Malabar and Columbus Jack. As an authorized Tronair distributor and GSE service center, we also have the certified technicians, OEM-spec procedures, and equipment to perform the 90-day inspections and annual load tests that keep your jacks operating within manufacturer specifications.

Whether you're looking to purchase, rent, or set up a lease-to-own program for aircraft jacks – or you need to schedule a 90-day inspection or annual load test with our GSE service center – our aviation specialists are ready to help. Reach out to us by phone, email, or live chat to get started.